In a general sense, the invention is directed to systems and methods for treating interior tissue regions of the body. More specifically, the invention is directed to systems and methods for treating dysfunction in body sphincters and adjoining tissue, e.g., in and around the lower esophageal sphincter and cardia of the stomach, or in and around the anal sphincter complex.
Dysfunction of a sphincter in the body can lead to internal damage or disease, discomfort, or otherwise adversely affect patient quality of life. Gastroesophageal reflux disease (GERD), for example, is a common disorder caused most commonly by frequent transient relaxations of the lower esophageal sphincter (LES). If the lower esophageal sphincter fails to function properly, stomach contents, including acid, enzymes, and bile may flow backwards into the esophagus, causing heartburn or other disease symptoms, damage to the esophagus, and the development of precancerous lesions.
Fecal incontinence is the involuntary passage of solid or liquid stool through the anal canal. This is caused most commonly by previous damage to or aging of the external and/or internal sphincter muscles in the anal canal. Secondary causes are improper sensing and control of solid or liquid stool within the rectum.
The disease states of GERD and fecal incontinence have in common a defective sphincter barrier as a mechanism of the disease. The end result is the development of GERD and fecal incontinence symptoms due to inadequate barrier function. In both GERD and fecal incontinence, inadequate barrier function can be the result of either a mechanical defect in the sphincter, a low resting pressure in the sphincter, an overly compliant sphincter, abnormal afferent nerve impulses that trigger transient sphincter relaxations, or improper sensing of and control of lumenal contents.
The invention provides systems and methods that apply a selected treatment agent into contact with tissue at, or in, the region of a dysfunctional sphincter in order to affect improved sphincter barrier function and improve a disease state. The systems and methods may be used as either a primary treatment modality, or applied as a supplementary treatment before, during or after a primary intervention.
According to one aspect of the invention, the treatment agent includes at least one sub-type of a cytokine. Delivery of a cytokine to tissue evokes a desired tissue response, which can include, e.g., an initiation of a localized healing process including influx of white blood cells and fibroblasts, followed by deposition of collagen, and a subsequent reduction in tissue compliance and tightening. These effects will result in improved sphincter barrier function. The cytokine treatment agent may be applied to the surface of a tissue, or, alternatively, it may be injected below the surface of the tissue, including the submucosa, the sphincter itself, or the area surrounding the sphincter.
According to another aspect of the invention, the treatment agent may include a tissue bulking agent, which is injected into subsurface tissue, including the submucosa, the sphincter, or the area surrounding the sphincter. Presence of the bulking agent results in additional tissue compliance reduction and tightening to improve sphincter barrier function.
According to another aspect of the invention, the treatment agent includes at least one vanilloid compound. Presence of the vanilloid compound evokes a desired tissue response, which includes at least one of the following, e.g., the interruption of afferent nerve impulses which lead to impaired sphincter function or diminished pain impulses from the treated area. The vanilloid treatment agent may be applied to surface tissue, or, alternatively, it may be injected into subsurface tissue, including the submucosa, the sphincter, or the area surrounding the sphincter. In one embodiment, the systems and methods apply energy to the tissue region to form at least one lesion in conjunction with application of the treatment agent.
Features and advantages of the inventions are set forth in the following Description and Drawings, as well as in the appended claims.